3.2.4 Slopes of Parallel and Perpendicular Lines Flashcards
1
Q
Parallel lines
A
lines in the same plane that have no points in common
2
Q
Perpendicular lines
A
lines that intersect to form right angles (90°)
3
Q
Parallel Lines Theorem
A
In a coordinate plane, two nonvertical lines are parallel if and only if they have the same slope. Any two vertical lines are parallel.
4
Q
Perpendicular Lines Theorem
A
In a coordinate plane, two nonvertical lines are perpendicular if and only if the product of their slopes is −1. Vertical and horizontal lines are perpendicular.
